God damn I wish someone would at least check this out to see if there is something of value.

The way I saw it was that, whenever close to a particular tile, the game would play ambience.
This is unlike the current set up where the owl, cricket, and bird ambience sounds play every once in a while.

For example:

When close to the water at the ocean, we could put in a waves crashing sound.

Please can someone check this out? I know there are a shit load of people who look at the code.

Ambient sounds are hard to alter. There's a few bird calls (not crows) a few owls and some crickets chirping loops. If you want to swap a bird for dog barking say it must not only be in the exact same format... it must also be near as damn it the exact same length or it will never play. I think rain, thunder and cows mooing are all semi ambient in a way but triggered by something else; in the cows case by being in the map of course.

Pretty snappy for somebody who likes telling other people off for being err... snappy.

The answer is in your name Tao. "It is only the emptyness of the vessel makes it useful" as Lao Tse would have put it. Just as a colour needs a background, ambient sounds from crickets to airstrikes need a blank backdrop to be measured against. That's my penith but I love the waves crashing on the coastal maps idea so much I think it's worth chasing up.

Did you figure it out?
Look in the map editor, the 'map info' button. You can set color scheme,"underground" luminosity,type of map (cave, outdoors, etc) and other stuff and it is from what you set there that the hour-related changes are applied. Don't think there's anything else to it...tileset related coding is elsewhere.